In the parent U.S. Pat. No. 7,430,074 “GENERATION OF TERAHERTZ WAVES” the generation of nonequilibrium magnons was disclosed. In the U.S. patent application Ser. No. 11/701,284, filed on Jan. 31, 2007 and entitled “MAGNON LASER”, the generation of nonequilibrium magnons was described by using a general laser analogy. In the U.S. patent application Ser. No. 12/290,527, filed on Nov. 1, 2008, and entitled “MAGNON LASER AT ROOM TEMPERATURES”, the generation of nonequilibrium magnons at room temperatures was disclosed by using special magnetic materials. In the U.S. patent application Ser. No. 13/043,470, filed on Mar. 9, 2011 and entitled “FOUR LEVEL MAGNON LASER AT ROOM TEMPERATURES”, the generation of nonequilibrium magnons was described by using a four level laser analogy.
In the present patent application an efficient technique for injection of electrical current into sub band having spin opposite to the direction of magnetization of the ferromagnetic conductive material is disclosed.